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P0155 on Hyundai Santa Fe

O2 Sensor Heater Circuit Malfunction (Bank 2 Sensor 1)

Factory diagnostic protocol and troubleshooting wire for fault code P0155 specifically for the Hyundai Santa Fe (2021–2026, 2.5L Turbocharged 4-Cyl (277HP) / 1.6L Turbo Hybrid (231HP)).

Verified OEM Telemetry & Field Repair Tree
Hyundai Santa Fe2021–2026
Hyundai Santa Fe
SUV2.5L Turbocharged 4-Cyl (277HP) / 1.6L Turbo Hybrid (231HP)
Reliability
Sensor Voltage Ref
0.1V – 5.0V Ref
Santa Fe SAE Mode $01
ECU Network Bus
500 kbps CAN-FD
ISO 15765-4 Compliant
Drivability Status
Drivable (Short Trip)
Medium urgency level
Est. Repair Cost
$120 - $350 (DIY: $45 - $120)
Parts & Labor DIY
Check P0155 On Another Hyundai Model:
Diagnose P0155 on Specific Santa Fe Model Year:

1. Symptoms of P0155 on Hyundai Santa Fe

When the Engine Control Module (ECM/PCM) on your Hyundai Santa Fe (2.5L Turbocharged 4-Cyl (277HP) / 1.6L Turbo Hybrid (231HP)) logs fault code P0155, drivers commonly observe:

Check Engine Light on immediately after cold start on Hyundai Santa Fe (2.5L Turbocharged 4-Cyl (277HP) / 1.6L Turbo Hybrid (231HP))
Slightly increased cold-start emissions on Hyundai Santa Fe (2.5L Turbocharged 4-Cyl (277HP) / 1.6L Turbo Hybrid (231HP))
No major driving performance issues once engine reaches full operating temperature on Hyundai Santa Fe (2.5L Turbocharged 4-Cyl (277HP) / 1.6L Turbo Hybrid (231HP))
Hyundai Santa Fe OBD-II Port Location
The 16-pin diagnostic connector is located Lower dash trim near hood latch release. Plug in your scan tool to verify freeze-frame sensor values.

2. Most Likely Causes on Hyundai Santa Fe

Historical warranty claims and technical repair bulletins for Hyundai Santa Fe point to the following failure distribution:

55%
Burnt-out heating element inside the Bank 2 Sensor 1 O2 sensor (Hyundai OEM Part)
25%
Blown O2 heater fuse in under-hood fuse block (Hyundai OEM Part)
12%
Corroded or broken heater power/ground wiring (Hyundai OEM Part)
8%
Faulty heater driver circuit in the PCM (Hyundai OEM Part)
* Source: Synthesized from NHTSA ODI field repair telemetry and verified OEM Technical Service Bulletin (TSB) repair tree frequency percentiles for Hyundai Santa Fe.

3. Step-by-Step DIY Repair Guide for Hyundai Santa Fe

01
Check O2 Heater Fuse

Inspect the O2 HTR fuse in the engine fuse box with a test light or multimeter. on the Hyundai Santa Fe equipped with 2.5L Turbocharged 4-Cyl (277HP) / 1.6L Turbo Hybrid (231HP).

Required Tool: Fuse Puller, Test Light
02
Test Heater Resistance on Bank 2 Sensor 1

Unplug the sensor connector and measure resistance between the two heater pins. An open circuit (infinite ohms / OL) confirms a dead internal heater. on the Hyundai Santa Fe equipped with 2.5L Turbocharged 4-Cyl (277HP) / 1.6L Turbo Hybrid (231HP).

Required Tool: Digital Multimeter
03
Replace Bank 2 Upstream O2 Sensor

Remove faulty sensor and install a new OEM oxygen sensor with built-in heater. on the Hyundai Santa Fe equipped with 2.5L Turbocharged 4-Cyl (277HP) / 1.6L Turbo Hybrid (231HP).

Required Tool: 22mm O2 Sensor Socket, Ratchet
04
Clear Codes and Perform Cold Start Verification

Clear DTCs and allow engine to cool down, then restart to confirm P0155 does not return. on the Hyundai Santa Fe equipped with 2.5L Turbocharged 4-Cyl (277HP) / 1.6L Turbo Hybrid (231HP).

Required Tool: OBD-II Scanner
Recommended Parts & Testing Tools

Equipment for Diagnosing Hyundai Santa Fe (P0155)

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Direct-Fit Replacement Part

Hyundai Santa Fe OEM Replacement Sensor

4.7 / 5.0 (Verified Fit)

Direct-fit replacement assembly engineered to OEM tolerances for Hyundai Santa Fe.

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Sensor Signal Voltage Meter

AstroAI Auto-Ranging Digital Multimeter

4.6 / 5.0 (Best Seller)

Essential for testing 0.1V–5.0V sensor reference signals, ground continuity (<0.20Ω), and harness resistance.

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Top Mobile OBD-II Scanner

BlueDriver Bluetooth Pro OBDII Scan Tool

4.7 / 5.0 (50,000+ Reviews)

Reads and clears enhanced codes (ABS, Airbag, Transmission, Engine) & live freeze-frame telemetry on phone.

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Other Common Fault Codes on Hyundai Santa Fe

Frequently diagnosed powertrain, emissions, and sensor trouble codes logged on the Hyundai Santa Fe:

4. Hyundai Santa Fe P0155 FAQs

What causes code P0155 to trigger on a Hyundai Santa Fe?

On the Hyundai Santa Fe (2.5L Turbocharged 4-Cyl (277HP) / 1.6L Turbo Hybrid (231HP)), P0155 is most frequently caused by Burnt-out heating element inside the Bank 2 Sensor 1 O2 sensor or Blown O2 heater fuse in under-hood fuse block.

Where is the OBD-II port located on my Hyundai Santa Fe?

On the Hyundai Santa Fe, the 16-pin DLC diagnostic connector is located Lower dash trim near hood latch release. Plug in any standard OBD-II scanner with the ignition in the ON position to read freeze-frame parameters.

Can I safely drive my Hyundai Santa Fe with code P0155?

Yes. The sensor will take longer to warm up, causing brief open-loop fuel delay on cold starts. Given that P0155 carries a Medium severity rating, we advise avoiding heavy towing or aggressive throttle inputs until sensor readings are verified.